Association of diabetes and cancer mortality in American Indians: the Strong Heart Study

Advancing environmental epidemiologic methods to confront the cancer burden

Even though many environmental carcinogens have been identified, studying their effects on specific cancers has been challenging in nonoccupational settings, where exposures may be chronic but at lower levels. Although exposure measurement methods have improved considerably, along with key opportunities to integrate multi-omic platforms, there remain challenges that need to be considered, particularly around the design of studies. Cancer studies typically exclude individuals with prior cancers and start recruitment in midlife. This translates into a failure to capture individuals who may have been most susceptible because of both germline susceptibility and higher early-life exposures that lead to premature mortality from cancer and/or other environmentally caused diseases like lung diseases. Using the example of breast cancer, we demonstrate how integration of susceptibility, both for cancer risk and for exposure windows, may provide a more complete picture regarding the harm of many different environmental exposures. Choice of study design is critical to examining the effects of environmental exposures, and it will not be enough to just rely on the availability of existing cohorts and samples within these cohorts. In contrast, new, diverse, early-onset case-control studies may provide many benefits to understanding the impact of environmental exposures on cancer risk and mortality. This article is part of a Special Collection on Environmental Epidemiology.

Formative Assessment to Improve Cancer Screenings in American Indian Men: Native Patient Navigator and mHealth Texting

Cancer screening rates among American Indian men remain low, without programs specifically designed for men. This paper describes the Community-Based Participatory Research processes and assessment of cancer screening behavior and the appropriateness of the mHealth approach for Hopi men's promotion of cancer screenings. This Community-Based Participatory Research included a partnership with H.O.P.I. (Hopi Office of Prevention and Intervention) Cancer Support Services and the Hopi Community Advisory Committee. Cellular phone usage was assessed among male participants in a wellness program utilizing text messaging. Community surveys were conducted with Hopi men (50 years of age or older). The survey revealed colorectal cancer screening rate increased from 51% in 2012 to 71% in 2018, while prostate cancer screening rate had not changed (35% in 2012 and 37% in 2018). Past cancer screening was associated with having additional cancer screening. A cellular phone was commonly used by Hopi men, but not for healthcare or wellness. Cellular phone ownership increased odds of prostate cancer screening in the unadjusted model (OR 9.00, 95% CI: 1.11-73.07), but not in the adjusted model. Cellular phones may be applied for health promotion among Hopi men, but use of cellular phones to improve cancer screening participation needs further investigation.

Renal Cell Carcinoma Surgical Treatment Disparities in American Indian/Alaska Natives and Hispanic Americans in Arizona

American Indians/Alaska Natives (AI/AN) and Hispanic Americans (HA) have higher kidney cancer incidence and mortality rates compared to non-Hispanic Whites (NHW). Herein, we describe the disparity in renal cell carcinoma (RCC) surgical treatment for AI/AN and HA and the potential association with mortality in Arizona. A total of 5111 stage I RCC cases diagnosed between 2007 and 2016 from the Arizona Cancer Registry were included. Statistical analyses were performed to test the association of race/ethnicity with surgical treatment pattern and overall mortality, adjusting for patients' demographic, healthcare access, and socioeconomic factors. AI/AN were diagnosed 6 years younger than NHW and were more likely to receive radical rather than partial nephrectomy (OR 1.49 95% CI: 1.07-2.07) compared to NHW. Mexican Americans had increased odds of not undergoing surgical treatment (OR 1.66, 95% CI: 1.08-2.53). Analysis showed that not undergoing surgical treatment and undergoing radical nephrectomy were statistically significantly associated with higher overall mortality (HR 1.82 95% CI: 1.21-2.76 and HR 1.59 95% CI: 1.30-1.95 respectively). Mexican Americans, particularly U.S.-born Mexican Americans, had an increased risk for overall mortality and RCC-specific mortality even after adjusting for neighborhood socioeconomic factors and surgical treatment patterns. Although statistically not significant after adjusting for neighborhood-level socioeconomic factors and surgical treatment patterns, AI/AN had an elevated risk of mortality.

Cancer mortality in a population-based cohort of American Indians - The strong heart study

BACKGROUND

Cancer mortality among American Indian (AI) people varies widely, but factors associated with cancer mortality are infrequently assessed.

METHODS

Cancer deaths were identified from death certificate data for 3516 participants of the Strong Heart Study, a population-based cohort study of AI adults ages 45-74 years in Arizona, Oklahoma, and North and South Dakota. Cancer mortality was calculated by age, sex and region. Cox proportional hazards model was used to assess independent associations between baseline factors in 1989 and cancer death by 2010.

RESULTS

After a median follow-up of 15.3 years, the cancer death rate per 1000 person-years was 6.33 (95 % CI 5.67-7.04). Cancer mortality was highest among men in North/South Dakota (8.18; 95 % CI 6.46-10.23) and lowest among women in Arizona (4.57; 95 % CI 2.87-6.92). Factors independently associated with increased cancer mortality included age, current or former smoking, waist circumference, albuminuria, urinary cadmium, and prior cancer history. Factors associated with decreased cancer mortality included Oklahoma compared to Dakota residence, higher body mass index and total cholesterol. Sex was not associated with cancer mortality. Lung cancer was the leading cause of cancer mortality overall (1.56/1000 person-years), but no lung cancer deaths occurred among Arizona participants. Mortality from unspecified cancer was relatively high (0.48/100 person-years; 95 % CI 0.32-0.71).

CONCLUSIONS

Regional variation in AI cancer mortality persisted despite adjustment for individual risk factors. Mortality from unspecified cancer was high. Better understanding of regional differences in cancer mortality, and better classification of cancer deaths, will help healthcare programs address cancer in AI communities.

The Relationship between Diabetes Mellitus and Gastric Cancer and the Potential Benefits of Metformin: An Extensive Review of the Literature

The objective of this review is to summarize the findings of published research that investigated the relationship between diabetes mellitus and gastric cancer (GCa) and the potential benefits of metformin on GCa. Related literature has been extensively reviewed, and findings from studies investigating the relationship between diabetes mellitus and GCa suggest that hyperglycemia, hyperinsulinemia and insulin resistance are closely related to the development of GCa. Although not supported by all, most observational studies suggest an increased risk of GCa in patients with type 2 diabetes mellitus, especially in women and in Asian populations. Incidence of second primary malignancy diagnosed after GCa is significantly higher in diabetes patients. Diabetes patients with GCa may have more complications after gastrectomy or chemotherapy and they may have a poorer prognosis than patients with GCa but without diabetes mellitus. However, glycemic control may improve in the diabetes patients with GCa after receiving gastrectomy, especially after procedures that bypass the duodenum and proximal jejunum, such as Roux-en-Y gastric bypass or Billroth II reconstruction. The potential links between diabetes mellitus and GCa may involve the interactions with shared risk factors (e.g., obesity, hyperglycemia, hyperinsulinemia, insulin resistance, high salt intake, smoking, etc.), Helicobacter pylori (HP) infection, medications (e.g., insulin, metformin, statins, aspirin, proton pump inhibitors, antibiotics, etc.) and comorbidities (e.g., hypertension, dyslipidemia, vascular complications, heart failure, renal failure, etc.). With regards to the potential benefits of metformin on GCa, results of most observational studies suggest a reduced risk of GCa associated with metformin use in patients with T2DM, which can be supported by evidence derived from many in vitro and animal studies. Metformin use may also reduce the risk of HP infection, an important risk factor of GCa. In patients with GCa, metformin users may have improved survival and reduced recurrence. More studies are required to clarify the pathological subtypes/anatomical sites of GCa associated with type 2 diabetes mellitus or prevented by metformin, to confirm whether GCa risk can also be increased in patients with type 1 diabetes mellitus and to explore the possible role of gastric microbiota in the development of GCa.

Diabetes mellitus and colorectal carcinoma outcomes: a meta-analysis

OBJECTIVES

The impact of diabetes mellitus (DM) on colorectal cancer (CRC) outcomes remains unknown. We studied this by conducting a meta-analysis to evaluate (1) CRC outcomes with and without DM and (2) treatment patterns.

METHODS

We searched PubMed, EMBASE, Google Scholar, and CINAHL for full-text English studies from 1970 to 12/31/2017. We searched keywords, subject headings, and MESH terms to locate studies of CRC outcomes/treatment and DM. Studies were evaluated by two oncologists. Of 14,332, 48 met inclusion criteria. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, we extracted study location, design, DM definition, covariates, comparison groups, outcomes, and relative risks and/or hazard ratios. We utilized a random-effects model to pool adjusted risk estimates. Primary outcomes were all-cause mortality (ACM), disease-free survival (DFS), relapse-free survival (RFS), and cancer-specific survival (CSS). The secondary outcome was treatment patterns.

RESULTS

Forty-eight studies were included, 42 in the meta-analysis, and 6 in the descriptive analysis, totaling > 240,000 patients. ACM was 21% worse (OR 1.21, 95% CI 1.15-1.28) and DFS was 75% worse (OR 1.75, 95% CI: 1.33-2.31) in patients with DM. No differences were detected in CSS (OR 1.10, 95% CI 0.98-1.23) or RFS (OR 1.12, 95% CI 0.91-1.38). Descriptive analysis of treatment patterns in CRC and DM suggested potentially less adjuvant therapy use in cases with DM and CRC.

CONCLUSIONS

Our meta-analysis suggests that patients with CRC and DM have worse ACM and DFS than patients without DM, suggesting that non-cancer causes of death in may account for worse outcomes.

Telomere length and cancer mortality in American Indians: the Strong Heart Study

The objective of this study was to investigate whether leukocyte telomere length (LTL) predicts the risk for cancer mortality among American Indians participating in the Strong Heart Study (1989-1991). Participants (aged 45-74 years) were followed annually until December 2015 to collect information on morbidity/mortality. LTL was measured by qPCR using genomic DNA isolated from peripheral blood. The association between LTL and risk for cancer mortality was examined using a multivariable Cox proportional hazard model, adjusting for age, gender, education, study site, smoking, alcohol use, physical activity, systolic blood pressure, fasting blood glucose, obesity, and low- and high-density lipoprotein. Of 1945 participants (mean age 56.10 ± 8.17 at baseline, 57% women) followed for an average 20.5 years, 220 died of cancer. Results showed that longer LTL at baseline significantly predicts an increased risk of cancer death among females (HR 1.57, 95% CI 1.08-2.30), but not males (HR 0.74, 95% CI 0.49-1.12) (p for interaction 0.009). Specifically, compared with the women with the longest LTL (fourth quartile), those in the third, second, and first quartiles showed 53%, 41%, and 44% reduced risk for cancer death, respectively. The findings highlight the importance of sex-specific analysis in future telomere research.

Diabetes Mellitus and Cause-Specific Mortality: A Population-Based Study

BACKGROUND

To investigate whether diabetes contributes to mortality for major types of diseases.

METHODS

Six National Health and Nutrition Examination Survey data cycles (1999 to 2000, 2001 to 2002, 2003 to 2004, 2005 to 2006, 2007 to 2008, and 2009 to 2010) and their linked mortality files were used. A population of 15,513 participants was included according to the availability of diabetes and mortality status.

RESULTS

Participants with diabetes tended to have higher all-cause mortality and mortality due to cardiovascular disease, cancer, chronic lower respiratory diseases, cerebrovascular disease, influenza and pneumonia, and kidney disease. Confounder-adjusted Cox proportional hazard models showed that both diagnosed diabetes category (yes or no) and diabetes status (diabetes, prediabetes, or no diabetes) were associated with all-cause mortality and with mortality due to cardiovascular disease, chronic lower respiratory diseases, influenza and pneumonia, and kidney disease. No associations were found for cancer-, accidents-, or Alzheimer's disease-related mortality.

CONCLUSION

The current study's findings provide epidemiological evidence that diagnosed diabetes at the baseline is associated with increased mortality risk due to cardiovascular disease, chronic lower respiratory diseases, influenza and pneumonia, and kidney disease, but not with cancer or Alzheimer's disease.

Proximate determinants of tuberculosis in Indigenous peoples worldwide: a systematic review

BACKGROUND

Indigenous peoples worldwide carry a disproportionate tuberculosis burden. There is an increasing awareness of the effect of social determinants and proximate determinants such as alcohol use, overcrowding, type 1 and type 2 diabetes, substance misuse, HIV, food insecurity and malnutrition, and smoking on the burden of tuberculosis. We aimed to understand the potential contribution of such determinants to tuberculosis in Indigenous peoples and to document steps taken to address them.

METHODS

We did a systematic review using seven databases (MEDLINE, Embase, CINAHL, Global Health, BIOSIS Previews, Web of Science, and the Cochrane Library). We identified English language articles published from Jan 1, 1980, to Dec 20, 2017, reporting the prevalence of proximate determinants of tuberculosis and preventive programmes targeting these determinants in Indigenous communities worldwide. We included any randomised controlled trials, controlled studies, cohort studies, cross-sectional studies, case reports, and qualitative research. Exclusion criteria were articles in languages other than English, full text not available, population was not Indigenous, focused exclusively on children or older people, and studies that focused on pharmacological interventions.

FINDINGS

Of 34 255 articles identified, 475 were eligible for inclusion. Most studies confirmed a higher prevalence of proximate determinants in Indigenous communities than in the general population. Diabetes was more frequent in Indigenous communities within high-income countries versus in low-income countries. The prevalence of alcohol use was generally similar to that among non-Indigenous groups, although patterns of drinking often differed. Smoking prevalence and smokeless tobacco consumption were commonly higher in Indigenous groups than in non-Indigenous groups. Food insecurity was highly prevalent in most Indigenous communities evaluated. Substance use was more frequent in Indigenous inhabitants of high-income countries than of low-income countries, with wide variation across Indigenous communities. The literature pertaining to HIV, crowding, and housing conditions among Indigenous peoples was too scant to draw firm conclusions. Preventive programmes that are culturally appropriate targeting these determinants appear feasible, although their effectiveness is largely unproven.

INTERPRETATION

Indigenous peoples were generally reported to have a higher prevalence of several proximate determinants of tuberculosis than non-Indigenous peoples, with wide variation across Indigenous communities. These findings emphasise the need for community-led, culturally appropriate strategies to address smoking, food insecurity, and diabetes in Indigenous populations as important public health goals in their own right, and also to reduce the burden of tuberculosis.

FUNDING

Canadian Institutes of Health Research.

Hyperglycemia, Classified with Multiple Biomarkers Simultaneously in Men without Diabetes, and Risk of Fatal Prostate Cancer

The association between hyperglycemia and prostate cancer risk is inconsistent, and its association with prostate cancer mortality is understudied. Thus, we investigated the association between hyperglycemia and prostate cancer risk and mortality using multiple biomarkers simultaneously to classify hyper- and normoglycemia. We conducted a prospective analysis of 5,162 cancer-free men attending visit 2 (1990-1992) of the Atherosclerosis Risk in Communities (ARIC) study followed for total (N = 671) and lethal (N = 69) prostate cancer incidence and prostate cancer mortality (N = 64) through 2012. Men without diagnosed diabetes were classified as normo- or hyperglycemic using joint categories of fasting glucose, glycated hemoglobin, and glycated albumin (or fructosamine) defined by clinical or research cutpoints. We evaluated the multivariable-adjusted association of hyperglycemia with prostate cancer incidence and mortality using Cox proportional hazards regression; men with diagnosed diabetes were included as a separate exposure category. Among 4,753 men without diagnosed diabetes, 61.5% were classified as having hyperglycemia (high on ≥1 biomarker). HbA1c and glycated albumin together classified 61.9% of 1,736 men with normal fasting glucose as normoglycemic. Compared with men who were normal on all three biomarkers, men who were high on ≥1 biomarker had an increased risk of lethal [HR, 2.50; 95% confidence interval (CI), 1.12-5.58] and fatal (HR, 3.20; 95% CI, 1.26-8.48) disease, but not total prostate cancer incidence (HR, 0.98; 95% CI, 0.81-1.20); associations were similar including fructosamine instead of glycated albumin. Our findings indicate hyperglycemia is associated with an increased risk of lethal and fatal prostate cancer, but not total prostate cancer incidence.

Arsenic in groundwater in private wells in rural North Dakota and South Dakota: Water quality assessment for an intervention trial

Elevated exposure to arsenic disproportionately affects populations relying on private well water in the United States (US). This includes many American Indian (AI) communities where naturally occurring arsenic is often above 10 µg/L, the current US Environmental Protection Agency safety standard. The Strong Heart Water Study is a randomized controlled trial aiming to reduce arsenic exposure to private well water users in AI communities in North Dakota and South Dakota. In preparation for this intervention, 371 households were included in a community water arsenic testing program to identify households with arsenic ≥10 µg/L by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic ≥10 µg/L was found in 97/371 (26.1%) households; median water arsenic concentration was 6.3 µg/L, ranging from <1-198 µg/L. Silica was identified as a water quality parameter that could impact the efficacy of arsenic removal devices to be installed. A low-range field rapid arsenic testing kit evaluated in a small number of households was found to have low accuracy; therefore, not an option for the screening of affected households in this setting. In a pilot study of the effectiveness of a point-of-use adsorptive media water filtration device for arsenic removal, all devices installed removed arsenic below 1 µg/L at both installation and 9 months post-installation. This study identified a relatively high burden of arsenic in AI study communities as well as an effective water filtration device to reduce arsenic in these communities. The long-term efficacy of a community based arsenic mitigation program in reducing arsenic exposure and preventing arsenic related disease is being tested as part of the Strong Heart Water Study.

Food choices and distress in reservation-based American Indians and Alaska Natives with type 2 diabetes

OBJECTIVE

To examine the association between food choice and distress in a large national sample of American Indians/Alaska Natives (AI/AN) with type 2 diabetes.

DESIGN

Participants completed a sociodemographic survey, an FFQ and the Kessler-6 Distress Scale. Foods were identified as 'healthy' or 'unhealthy' using a classification grounded in the health education provided by the programme case managers; healthy and unhealthy food scores were calculated using reported intake frequencies. Pearson's correlation coefficients for distress and food scores were calculated for all participants and by gender. Multiple linear regression models stratified by gender assessed the association between distress and food scores, controlling for sociodemographics and duration of type 2 diabetes.

SETTING

Rural AI reservations and AN villages.

SUBJECTS

AI/AN (n 2484) with type 2 diabetes.

RESULTS

Both males (34·9 %) and females (65·1 %) had higher healthy food scores than unhealthy scores. In bivariate analysis, distress level had a significant negative correlation with healthy food scores among female participants, but the association was not significant among males. Significant positive correlations between distress and unhealthy food scores were found in both genders. In the final multivariate models, healthy food scores were not significantly related to distress; however, unhealthy food scores showed significant positive relationships with distress for both genders (females: β=0·078, P=0·0007; males: β=0·139, P<0·0001).

CONCLUSIONS

Health professionals working with AI/AN diagnosed with type 2 diabetes should offer food choice strategies during difficult times and recognize that males may be more likely than females to select unhealthy foods when distressed.

Diabetes mellitus and the risk of gastric cancer: a meta-analysis of cohort studies

Studies examining the relationship between diabetes mellitus (DM) and the risk of gastric cancer incidence or gastric cancer mortality have produced inconsistent results. The purpose of this study was to evaluate the evidence regarding the relationship between DM and subsequent gastric cancer incidence or gastric cancer mortality risk on the basis of cohort studies. A systematic search of articles in PubMed, EmBase, the Cochrane Library, and reference lists was conducted to identify relevant literature. Twenty-two cohort studies reporting data on 8,559,861 participants were included in the study. Overall, participants with DM had little or no change in the risk of gastric cancer, or gastric cancer mortality. There was no evidence of difference in the RR for gastric cancer between men and women. Participants with DM had a non-significant trend towards an increased risk of gastric cancer mortality in men. There was no significant difference between men and women for this relationship. Finally, although subgroup analysis suggested DM was associated with a significant impact on gastric cancer incidence and gastric cancer mortality risk in several specific populations, a significance based on gender difference was not observed. In conclusion, DM might increase the risk of gastric cancer in men when the study used standard incidence/mortality ratio as effect estimate. Further, DM were associated with higher risk of gastric cancer mortality in men if the mean age at baseline less than 55.0 years, used RR or HR as effect estimate, the study adjusted smoking or not, and the study not adjusted alcohol drinking.

Serum microRNA profiling and bioinformatics analysis of patients with type 2 diabetes mellitus in a Chinese population

Type 2 diabetes mellitus (T2DM) is characterized by islet β-cell dysfunction and insulin resistance, which leads to an inability to maintain blood glucose homeostasis. Circulating microRNAs (miRNAs) have been suggested as novel biomarkers for T2DM prediction or disease progression. However, miRNAs and their roles in the pathogenesis of T2DM remain to be fully elucidated. In the present study, the serum miRNA expression profiles of T2DM patients in Chinese cohorts were examined. Total RNA was extracted from serum samples of 10 patients with T2DM and five healthy controls, and these was used in reverse-transcription‑quantitative polymerase chain reaction analysis with the Exiqon PCR system of 384 serum/plasma miRNAs. A total of seven miRNAs were differentially expressed between the two groups (fold change >3 or <0.33; P<0.05). The serum expression levels of miR‑455‑5p, miR‑454‑3p, miR‑144‑3p and miR‑96‑5p were higher in patients with T2DM, compared with those of healthy subjects, however, the levels of miR‑409‑3p, miR‑665 and miR‑766‑3p were lower. Hierarchical cluster analysis indicated that it was possible to separate patients with T2DM and control individuals into their own similar categories by these differential miRNAs. Target prediction showed that 97 T2DM candidate genes were potentially modulated by these seven miRNAs. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that 24 pathways were enriched for these genes, and the majority of these pathways were enriched for the targets of induced and repressed miRNAs, among which insulin, adipocytokine and T2DM pathways, and several cancer‑associated pathways have been previously associated with T2DM. In conclusion, the present study demonstrated that serum miRNAs may be novel biomarkers for T2DM and provided novel insights into the pathogenesis of T2DM.

Diabetes and mortality in patients with prostate cancer: a meta-analysis

BACKGROUND

There are conflicting results as to the association between pre-existing diabetes and the risk of mortality in patients with prostate cancer. The purpose of this study is to estimate the influence of pre-existing diabetes on prostate cancer-specific mortality and all-cause mortality.

METHODS

We searched PubMed and Embase to identify studies that investigated the association between pre-existing diabetes and risk of death among men with prostate cancer. Pooled risk estimates and 95 % confidence intervals were calculated using fixed-effects models or random-effects models. Heterogeneity tests were conducted between studies. Publication bias was analyzed by using the Egger's test, Begg's test, and the trim and fill method.

RESULTS

Of the 733 articles identified, 17 cohort studies that had 274,677 male patients were included in this meta-analysis. Pre-existing diabetes was associated with a 29 % increase in prostate cancer-specific mortality [relative risk (RR) 1.29, 95 % CI 1.22-1.38, I(2) = 66.68 %], and with a 37 % increase in all-cause mortality (RR 1.37, 95 % CI 1.29-1.45, p < 0.01, I(2) = 90.26 %). Additionally, in a subgroup analysis that was a type specific analysis focusing on type 2 diabetes and was conducted only with three cohort studies, pre-existing type 2 diabetes was associated with all-cause mortality (RR 2.01, 95 % CI 1.37-2.96, I(2) = 95.55 %) and no significant association with prostate cancer-specific mortality was detected (RR 1.17, 95 % CI 0.96-1.42, I(2) = 75.59 %). There was significant heterogeneity between studies and no publication bias was found.

CONCLUSIONS

This meta-analysis suggests diabetes may result in a worse prognosis for men with prostate cancer. Considering heterogeneity between studies, additional studies should be conducted to confirm these findings, and to allow generalization regarding the influence that each type of diabetes has on prostate cancer mortality.

Milk: an epigenetic amplifier of FTO-mediated transcription? Implications for Western diseases

Single-nucleotide polymorphisms within intron 1 of the FTO (fat mass and obesity-associated) gene are associated with enhanced FTO expression, increased body weight, obesity and type 2 diabetes mellitus (T2DM). The N⁶-methyladenosine (m⁶A) demethylase FTO plays a pivotal regulatory role for postnatal growth and energy expenditure. The purpose of this review is to provide translational evidence that links milk signaling with FTO-activated transcription of the milk recipient. FTO-dependent demethylation of m⁶A regulates mRNA splicing required for adipogenesis, increases the stability of mRNAs, and affects microRNA (miRNA) expression and miRNA biosynthesis. FTO senses branched-chain amino acids (BCAAs) and activates the nutrient sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), which plays a key role in translation. Milk provides abundant BCAAs and glutamine, critical components increasing FTO expression. CpG hypomethylation in the first intron of FTO has recently been associated with T2DM. CpG methylation is generally associated with gene silencing. In contrast, CpG demethylation generally increases transcription. DNA de novo methylation of CpG sites is facilitated by DNA methyltransferases (DNMT) 3A and 3B, whereas DNA maintenance methylation is controlled by DNMT1. MiRNA-29s target all DNMTs and thus reduce DNA CpG methylation. Cow´s milk provides substantial amounts of exosomal miRNA-29s that reach the systemic circulation and target mRNAs of the milk recipient. Via DNMT suppression, milk exosomal miRNA-29s may reduce the magnitude of FTO methylation, thereby epigenetically increasing FTO expression in the milk consumer. High lactation performance with increased milk yield has recently been associated with excessive miRNA-29 expression of dairy cow mammary epithelial cells (DCMECs). Notably, the galactopoietic hormone prolactin upregulates the transcription factor STAT3, which induces miRNA-29 expression. In a retrovirus-like manner milk exosomes may transfer DCMEC-derived miRNA-29s and bovine FTO mRNA to the milk consumer amplifying FTO expression. There is compelling evidence that obesity, T2DM, prostate and breast cancer, and neurodegenerative diseases are all associated with increased FTO expression. Maximization of lactation performance by veterinary medicine with enhanced miRNA-29s and FTO expression associated with increased exosomal miRNA-29 and FTO mRNA transfer to the milk consumer may represent key epigenetic mechanisms promoting FTO/mTORC1-mediated diseases of civilization.